It’s a tripod which is “self-incompatible” and male sterile; it destroys aberrant meiosis and is hence incapable of independent sexual reproduction–all propagation is by vegetative multiplication through manual “divide-and-set” of a rookie clone or by interspecific hybridisation.
And similar climates where warm and dry summer breezes sweep semi-arid lands. It can nevertheless survive cold winters, tolerating frosts as low as −10 °C (14 °F) and brief periods of snow cover. Irrigation is needed if grown outside of moist environments like Kashmir, where annual rainfall averages 1,000–1,500 mm (39–59 in); saffron-growing areas in Greece (500 mm or 20 in yearly) and Spain (400 mm or 16 in) are far drier than the primary cultivating Iranian regions. What makes this possible is that the timing of the community rainy seasons; generous spring rains and dryer summers are optimal. Rain immediately preceding flowering promotes saffron yields; rainy or chilly weather during flowering promotes disease and reduces yields. Persistently moist and hot conditions harm the plants, and rabbits, rats, and birds cause damage by digging up corms. Nematodes, leaf rusts, and corm corrosion pose additional dangers. Nevertheless Bacillus subtilis inoculation may offer some advantage to growers by hastening corm expansion and increasing stigma biomass yield.
The plants fare badly in shady conditions; they grow best in full sunlight. Fields that slope to the sun are best (i.e., south-sloping from the Northern Hemisphere). Planting is largely performed in June in the Northern Hemisphere, where corms are lodged 7–15 cm (3–6) deep; its own roots, stalks, and leaves can grow between October and February. Planting depth and corm spacing, in concert with climate, are crucial elements in determining yields. Mother corms planted deeper return higher-quality saffron, though form fewer flower buds and daughter corms. Greek, Moroccan, and Spanish growers employ different depths and spacings that match their locales.
Traditional raised beds encourage good drainage. Soil organic content was boosted via application hectare. Afterwards, and without an Additional manure application, corms were planted. Following a period of dormancy throughout the summer, the corms ship up their Narrow leaves and start to bud in early fall. They flower. Harvests are by necessity a quick affair: after blossoming At dawn, blossoms quickly wilt as the day moves. All plants bloom in a window of a couple of weeks. Stigmas are dried fast upon extraction and (preferably) sealed in airtight containers.